Stitch-forming mechanism for sewing-machines



' M. T. DENNE.

STITCH FORMING MECHANISM FOR SEWING MACHINES. APPLICATION FILED SEPT. 30, 1918.

1,346, 1 83. a t d uly 13, 1920.

JMML.

Mum Thomas Denna by W5MW UNITED STATES PATENT OFFICE.

MARK THOMAS DENNE, OF RUSHDEN, ENGLAND.

Specification-of Letters Patent.

Patented July 13, 1920.

Original application-filed September 22, 1914, Serial No. 863,025. Divided and this application fi1ed September 30, 1918.

To all whom it may concern:

Be it known that I, MARK THOMAS DENNE, a subject of the King of Great Britain and Ireland, residing at Rushden, Northamptonshire, England, have invented new and useful Improvements in Stitch-Forming Mechanism for SeWing-Machines, of which the following is a specification.

This invention has reference to improvements in the stitcl1-forming mechanism of sewing machines, more particularly sewing machines of the type known as outsole stitchers used for stitching the outsole to the welt or to the middle sole of boots and shoes and in which a curved needle and a curved awl are employed; and it consists mainly in stitch forming mechanism comprising a rotary' shuttle having a hook, and a shuttle race consisting of an inner fixed member, the acting face of which is formed with a projecting conical ridge, and an outer member having a Hat face and capable of being adjusted laterally by sliding over the said inner member, the said shuttle being formed with a lateral groove with which the projecting ridge of the said fixed member engages. The invention also comprises the provision of a loop spreader adapted to be reciprocated in a plane substantially at right angles to the plane in which the shuttle rotates and to open out the thread loop as hereinafter described.

A shuttle race constructed in accordance with my invention gives a continuous or substantially continuous bearing to the shuttle notwithstanding the necessary gap in front of the point of the hook. In shuttles and shuttle races as constructed heretofore the shuttle has a certain amount of lateral play when the gap in front of the hook point is passing the corresponding gap in the raceway and unequal wear results and my in-' vention obviates that defect.

The invention is illustrated in the accompanying drawing as applied to the outsole stitching machine illustrated in my Patent No. 1,301,400, dated April 22, 1919. The present application is a division of the application Se. No. 863,025, which matured into said patent.

Figure 1 shows my improved rotary shuttle and raceway partly in section, the needle and a loop opener which cooperates with the shuttle being also shown; and

Fig. 2 is an end view of the shuttle.

Serial No. 256.211.

1 indicates a rotary shuttle constructed to receive the thread mass and which is provided with a hook. This shuttle is formed on its rear face withan annular V-shaped groove 20 which is situated near the periphcry and on its front face with a flat surface 21. The shuttle is received in a shuttle raceway consisting of an inner fixed member 2 and an outer member 5. The inner member 2 is provided with an arcuate portion 8 which is formed with a conical or V-shaped ridge 4 of a shape to fit the V-shaped groove 20 in the rear face of the rotary shuttle. The outer member 5 has a fiat face 6 which is arranged to engage the fiat face 21 of the shuttle and thus hold the shuttle on the ridge 1. The outer member 5 is made capable of adjustment laterally by sliding over the inner member 2. The cone-shaped bearing portion 4 serves in a very efficient manner to hold the shuttle properly centered during its rotation and the cooperation of the flat face 6 with the shuttle holds the latter against movement in an axial direction. This construction has the advantage that notwithstanding wear which will eventually occur, the shuttle will still be maintained properly centered and any wear can be easily taken up by adjustment of the member 5. The shuttle may be actuated by a shuttle driver 22 in any known manner.

The needle 7 has its barb on the outer side and consequently the thread loop lies in a plane parallel with the needle axis, and as it is desired to deal with one side only of the loop in order to open it out to allow of the shuttle point readily entering it a loop opener 8 is provided which catches one side of the thread loop and then moves to a position-indicated in dot-and-dash linesoutside the plane of the front of the shuttle. A triangular loop is thus formed, the upper limb of which is approximately parallel with the flat chisel point of the shuttle hook and approximately horizontal. The shuttle then takes the loop and casts it over itself in the ordinary way.

The loop spreader 8 is carried on a slide 9 in a fitting 10 adjustably secured to the frame of the machine and is operated by a cam lever 11 through the intermediary of a second lever 12.

What I claim as my invention and desire to secure by Letters Patent is In a sewing machine, the combination with and an outer member having a flat face and capable of being adjusted toward andfrom said ridge, of a rotary shuttle provided with a hook and mounted in said raceway, said shuttle havingan annular V-shaped groove on its rear face adjacent the periphery,

which groove fits the V-shaped ridge of the 10 raceway and said shuttle having on its front face a fiat radial surface at its periphery which engages the fiat face of the outer member of the raceway.

In testimony whereof I have name to this specification.

MARK THOMAS DENNE'.

signed my 15 

